The field of this invention relates to the construction of a tractor for the towing of wheeled land vehicles such as house trailers, boat trailers, or any kind of trailer. Also, the apparatus of this invention is useful for moving airplanes into and out of a hangar.
The apparatus of this invention is considered to be an improvement of the tractor apparatus which is shown and described in U.S. Pat. No. 3,166,141, patented Jan. 19, 1965.
The tractor construction of the above-mentioned patent includes a pair of stabilizing arms and trailing caster wheels which are considered to be required in order to prevent the motorized dolly from overturning backwards when pulling a trailer forwards. The stabilizing arms and their associated trailing caster wheels are mounted aft of the driving wheels of the tractor or between the driving wheels of the tractor and the vehicle being moved. The use of the stabilizing arm and trailing caster wheels are a costly addition to the tractor structure. Although costly, it was just accepted that such are necessary in order to resist the overturning moment. With the use of such stabilizing arms and trailing caster wheels, the connecting and disconnecting of the tractor to the vehicle to be moved is accomplished quite quickly and with relative simplicity. However, on some trailers with roll prevention devices, said trailing caster wheels get in the way.